spelling fixes

cylc/flow/xtriggers/echo.py

@@ -27,7 +27,7 @@ def echo(*args, **kwargs) -> Tuple:
     This may be a useful aid to understanding how xtriggers work.
 
     Args:
-        succeed: Set the succeess of failure of this xtrigger.
+        succeed: Set the success of failure of this xtrigger.
         *args: Print to stdout.
         **kwargs: Print to stdout, and return as output.
 

cylc/flow/xtriggers/xrandom.py

@@ -68,7 +68,7 @@ def xrandom(
 
         Finally, if the percent is not zero, and the random percent success is
         met, then it returns that the trigger condition was satisfied, and a
-        dictionary containing random color and size as result.
+        dictionary containing random colour and size as result.
 
         >>> import sys
         >>> mocked_random = lambda: 0.9
@@ -87,7 +87,7 @@ def xrandom(
             A dictionary containing the following keys:
 
             ``COLOR``
-                A random color (e.g. red, orange, ...).
+                A random colour (e.g. red, orange, ...).
             ``SIZE``
                 A random size (e.g. small, medium, ...).